Simplify ••• WiFi ••• LocoFi™
As an Engineer, I would posit that the brass shell would act as a concentrating element for the Locofi PCB antenna inside. I doubt this would be possible at any frequency below about 1 GHz. The 2.4 GHz at which Wifi/Bluetooth operate should present no problem, I would think.
Here is my installation of a LocoFi in an HO Sunset 4-8-2 brass engine and tender.
I set up and painted this loco years ago for DC-only operation but included connectors and a speaker in the tender to make it easy to convert to a DCC board in the boiler later. Recently I revised it to install the LocoFi 3 board in the tender just in case it needed a hole to receive a wifi signal. I had already epoxy glued a speaker in place so I used it instead of the LocoFi speaker. I try to make components removable so I drilled holes and cut slots in the tender floor for the wiring so I wouldn't have connectors visible between the loco and tender. Later, the visible wires were painted with Tamiya acrylic Rubber Black.
It has a NWSL 240-6 gearbox, an A-Line universal joint and a brass torque arm.
The loco has a 1.5 volt micro bulb for a headlight that I didn't want to change so I added a second bulb in series so they would operate on the LocoFi headlight circuit. For sound I used Audacity to edit a steam hiss with some clanking sounds for the startup, running and shutdown. I kept the volume low so it was just a placeholder instead of using the "silent" WAV file. When the LocoFi steam sound is released I'll upgrade to it. I'll probably also add a capacitor to power the board for one or two seconds -- thanks scott589 for the post above on that topic.
Installed the DDLLHB system that was modified for use with an H-bridge in an O scale 2-rail steam locomotive's brass tender. [Sorry no steam and whistle sounds] The tender has only 2 small holes in it to route pick- up wires from the tender's trucks and the speaker wires. The speaker is located in a coal load separate from the brass body of the tender. Literally the LocoFi system and the H-bridge are housed in a 100% brass envelope. Reception was perfect when operating on a home layout 30' x 30'. From past experience operating a 2-rail diesel locomotive on my club's large layout, fitted with LocoFi, I need to use a router because of the size of the layout and will do the same with the steam locomotive. Don't forsee any problems. Do not see the need or concern for an external antenna with LocoFi.
There is a huge 2-rail O scale club layout that I want to take the brass locomotive to that has very large and long tunnels. I may have to use more than one router. Time will tell and not a problem if I have to use an additional router or two. With latest LocoFi software update my concern of losing a single and experiencing a runaway locomotive have also been eliminated.
Good job LocoFi !!!!
Was pleasantly surprised because past experiences with certain, brand L, 3 rail locomotives, reception has been a problem on some club layouts and an external antenna had to be fitted to the locomotive plus amplification of the 3 rail signal was required.
Another plus for LocoFi over the competition !!!!
My plan is similar to yours with modifying the coal load but was thinking about using a non metalic mesh to glue the coal onto. Since my coal load is large I am also going to mount my oversize speaker under the mesh. The mesh may give me more " free air" space rather than a solid . Will advise as things progress.
Was very informative and especially about the size opening in the unit related to being able to communicate with the LocoFi system. I am in the process of installing a LocoFi 3 system in the brass tender of a steam locomotive. It only has two 1/8 " Dia. holes in the base for the power lead wires leading up from the tender's trucks.
My concern is, the same as yours was, is how the LocoFi system is going to perform with virtually no access hole(s). Has LocoFi provided you with any information on how to or where to install an antenna with a LocoFi system?
With a plastic shell diesel locomotive fitted with the older LocoFi system i have to use a router on our club's layout because of its size of the layout. The reception is perfect which undoubtedly will be the same setup I will require with the brass locomotive and tender.
We have performed laboratory tests using enclosures of aluminum foil and we did not notice any marked reduction in WiFi signal as long as there was at least a small opening somewhere. Metal enclosures in general would tend to just reduce the range of the WiFi signal. Worst case, we may need to extend the antenna outside of the enclosure.
Please do note that LocoFi™ isn't yet available in "steam" sound scheme.